1. Field of the Invention
This invention relates to a structure for and method of mounting an image taking element such as a CCD on a substrate.
2. Description of the Related Art
There have been in wide use image taking elements such as a CCD. Generally such an image taking element is provided with a plurality of pins for electrical connection on one side thereof and is mounted on a substrate provided with a plurality of pads for electrical connection with the pins on the element. Further there has been known a structure in which the pads are provided on the image taking element and the pins are provided on the substrate.
Recently there has been provided a back-exposure type image taking element which is provided with a sensor portion on one side thereof and with a light receiving face on the side opposite to said one side as disclosed, for instance, in Japanese Unexamined Patent Publication Nos. 6(1994)-318688 and 6(1994)-318689.
The back-exposure type image taking element is advantageous over the normal image taking elements, which have a light receiving face on the side on which the sensor portion is provided, in that they are higher in sensitivity and have sufficient sensitivity even for ultraviolet rays.
However since it is necessary that the distance between the light receiving face and the sensor portion is very small in order to obtain a sufficient sensitivity, the back-exposure type image taking element is very small in its overall thickness. Therefore the back-exposure type image taking element is apt to be damaged by external force when mounting the element on a substrate and mounting yield is very low.
Though methods of mounting such a back-exposure type image taking element are disclosed in Japanese Unexamined Patent Publication Nos. 6(1994)-318688 and 6(1994)-318689, these methods cannot substantially increase the mounting yield.